Predictive value of the duration of positive nucleic acid test on the clinical outcome of COVID‑19 patients

ABSTRACT

Objective: To explore the predictive value of the duration of positive SARS‐CoV‐2 nucleic acid test in patients with coronavirus disease 2019 (COVID‐19) on clinical outcome. Methods: A total of 128 COVID‐19 patients admitted to Renmin Hospital of Wuhan University from March 2020 to May 2020 were selected and received symptomatic treatment. According to the clinical outcome of the patients, they were divided into a cured group (88 cases) and a death group (40 cases). The gender, age, time from onset to first diagnosis, clinical manifestations, past history, chest CT manifestations, respiratory support methods, blood gas indexes, the first laboratory test result after admission, and the duration of nucleic acid positive were compared between the two groups. Multivariate logistic regression analysis was used to determine the influencing factors of the clinical outcome of patients, and the ROC curve for each index was drawn to predict the clinical outcome of COVID‐19 patients. Results: Statistically significant difference between cure group and death group was found in age, arterial oxygen partial pressure, blood oxygen saturation, white blood cell count, neutrophil count, lymphocyte count, platelet count, urea nitrogen, blood potassium, D‐dimer, lactic acid, serum IL‐10, TNF‐α, and nucleic acid positive duration (P<0. 05). Multivariate logistic regression analysis showed that arterial blood oxygen partial pressure (OR=0. 602, 95%CI 0. 411 ‐ 0. 882), lymphocyte count (OR= 0. 710, 95%CI 0. 534 ‐ 0. 944), blood potassium (OR=2. 166, 95%CI 1. 223 ‐ 3. 836), lactic acid (OR=2. 675, 95%CI 1. 311 ‐ 5. 458), and nucleic acid positive duration (OR=1. 894, 95%CI 1. 248‐2. 874) were the influencing factors of the clinical outcome of patients (P<0. 05). The areas under the ROC curve of lactate, arterial partial pressure of oxygen, nucleic acid positive duration, blood potassium, and lymphocyte count to predict the clinical outcome of patients were 0. 922 (95%CI 0. 8867 ‐ 0. 968) and 0. 897 (95%CI 0. 837 ‐ 0.957), 0.854 (95%CI 0. 778 ‐ 0. 931), 0. 731 (95%CI 0. 637‐0. 826), and 0. 704 (95%CI 0. 608‐0. 812), respectively, which showed higher predictive value, and their best cut‐off values were 3. 35 mmol/L, 62 mmHg, 31 d, 4. 22 mmol/L, and 0. 91×109/ L, respectively, the sensitivities were 0. 914, 0. 906, 0. 844, 0. 750, and 0. 711, respectively, and the specificities were 0. 766, 0. 797, 0. 813, 0. 836, and 0. 820, respectively. Conclusion: Arterial partial pressure of oxygen, lymphocyte count, blood potassium, lactic acid, and nucleic acid positive duration are the influencing factors for the clinical outcome of COVID‐19 patients, and have a high predictive value for the death of the patients. © 2022 Editorial Board of Medical Journal of Wuhan University. All rights reserved.